Collision avoidance signaling from mobile devices

ABSTRACT

A location of a target associated with a first system is determined at the first system at a first time. A signal is constructed at the first system where the data of the signal includes a unique identifier, an identifier indicative of a collision avoidance nature of the signal, and the location of the target. The signal is broadcast from the first system. the broadcasting causes a second system to receive the signal; compute a likelihood of a collision between the first system and the second system using the location from the signal, a velocity of the first system, a location of the second system at the first time, and a velocity of the second system at the first time; and send a notification from the second system about the likelihood of collision when the likelihood of collision exceeding a threshold likelihood.

TECHNICAL FIELD

The present invention relates generally to a method, system, andcomputer program product for avoiding a collision between a vehicle andother participants of road traffic. More particularly, the presentinvention relates to a method, system, and computer program product foravoiding vehicle collision using signals from mobile devices.

BACKGROUND

Wireless communications (mobile communications) enable users to performa variety of tasks using their mobile devices. An ever increasing numberof applications is available for the wireless data processing systems,wireless data communication devices, or wireless computing platforms(collectively and interchangeably referred to herein as “mobile device”or “mobile devices”). For example, many mobile devices not only allowthe users to make voice calls, but also exchange emails and messages,access remote data processing systems, determine a user's location oractivity, communicate with other mobile devices or data processingsystems, or perform web-based interactions and other transactions.

Wearable devices are a category of mobile devices. A wearable device isessentially a mobile device, but has a form-factor that is suitable forwearing the device on a user's person. A user can wear such a device asan article of clothing, clothing or fashion accessory, jewelry, aprosthetic or aiding apparatus, an item in an ensemble carried by orwith a person, an article or gadget for convenience, and the like. Someexamples of presently available wearable devices include, but are notlimited to, smart watches, interactive eyewear, devices embedded infootwear, devices wearable as rings or pendants, and pedometers andother clip-ons.

Some wearable devices are independent wearable devices in that they canoperate as stand-alone mobile devices. Such a wearable device eitherincludes some or all the capabilities of a mobile device described aboveor does not need or use the capabilities of a mobile device describedabove.

Other wearable devices are dependent wearable devices in that theyoperate in conjunction with a mobile device. Such a wearable deviceperforms certain functions while in communication with a mobile devicedescribed above.

Hereinafter, any reference to a mobile device, or simply “device”, isintended to be inclusive of a mobile device of any kind that is capableof data communications, a wearable device that is capable of datacommunications—in a dependent or independent manner, or some combinationthereof. Hereinafter, any reference to a wearable device, or simply a“wearable” or “wearables”, is intended to be inclusive of a mobiledevice of any kind that is capable of data communications, a wearabledevice that is capable of data communications—in a dependent orindependent manner, or some combination thereof.

A variety of wireless protocols enable communications to and from themobile devices. For example, wireless standards such as FourthGeneration (4G) Long Term Evolution (LTE) allow data communication aswell as voice communication on mobile devices. Bluetooth and BluetoothLE protocols allow short-range device-to-device or device-to-dataprocessing system communications.

SUMMARY

The illustrative embodiments provide a method, system, and computerprogram product. An embodiment includes a method that determines at afirst system, at a first time, a location of a target associated withthe first system. The embodiment further constructs a signal, data ofthe signal comprising (i) a unique identifier, (ii) an identifierindicative of a collision avoidance nature of the signal, and (iii) thelocation of the target. The embodiment further broadcasts the signalfrom the first system, the broadcasting causing a second system toreceive the signal; compute, using the location from the signal and avelocity of the first system, and further using a location of the secondsystem at the first time and a velocity of the second system at thefirst time, a likelihood of a collision between the first system and thesecond system; and send a notification from the second system about thelikelihood of collision responsive to the likelihood of collisionexceeding a threshold likelihood.

An embodiment includes a computer usable program product. The computerusable program product includes one or more computer-readable storagedevices, and program instructions stored on at least one of the one ormore storage devices.

An embodiment includes a computer system. The computer system includesone or more processors, one or more computer-readable memories, and oneor more computer-readable storage devices, and program instructionsstored on at least one of the one or more storage devices for executionby at least one of the one or more processors via at least one of theone or more memories.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself, however, as well asa preferred mode of use, further objectives and advantages thereof, willbest be understood by reference to the following detailed description ofthe illustrative embodiments when read in conjunction with theaccompanying drawings, wherein:

FIG. 1 depicts a block diagram of a network of data processing systemsin which illustrative embodiments may be implemented;

FIG. 2 depicts a block diagram of a data processing system in whichillustrative embodiments may be implemented;

FIG. 3 depicts a block diagram of an example configuration for avoidingvehicle collision using signals from mobile devices in accordance withan illustrative embodiment;

FIG. 4A depicts a position plotting using map data in accordance with anillustrative embodiment;

FIG. 4B depicts a velocity plotting using map data in accordance with anillustrative embodiment;

FIG. 4C depicts a map plotting of a risk of collision in accordance withan illustrative embodiment;

FIG. 5 depicts a flowchart of an example process for avoiding vehiclecollision using signals from mobile devices in accordance with anillustrative embodiment; and

FIG. 6 depicts a process for configuring and broadcasting a collisionavoidance signal in accordance with an illustrative embodiment.

DETAILED DESCRIPTION

As compared to the speeds attainable by a powered vehicle, manyoccupants of the roads are relatively slow-moving. Some examples of theslow-moving occupants of the roads include pedestrians, riders ofbicycles, skates, and other human-powered apparatus, and the like. Aslow-moving occupant of roads and other pathways is interchangeablyreferred to herein as “target”. Hereinafter, a “vehicle” is a poweredvehicle, e.g., a motorized vehicle or automotive, such as including butnot limited to a motorcycle, car, truck, or a bus.

Powered vehicles involved in accidents with slow-moving occupants of theroad are a source of danger to life and limb of all involved, andgenerally to a far greater degree of the slow-moving occupants. Manyautomotive manufacturers are constantly working on increasing the safetyof the occupants of the automotive, and even of some slow-movingoccupants of the road to some extent, with the addition of sophisticateddriver assistance technologies. Many of these technologies use sonars,radars, and even lasers to detect the presence of other vehicles,pedestrians, debris, and other obstructions in the path of a vehicle.Many modern “connected” cars already come with a variety of driverassistance systems, which include emergency braking to avoid collisionsbetween a vehicle and other vehicles, pedestrians, and otherobstructions. Some of these technologies have a field of view thatprovides detection capabilities around the entire vehicle within somespecified range or distance from the vehicle.

However, the illustrative embodiments recognize that the presentlyavailable driver assistance technologies in the presently availablevehicles are still in their nascent stage, and are woefully inadequatefor detecting obstructions in a large number of real-worldcircumstances. For example, targets, such as bicycles, are commonlypresent in populated areas where sidewalks are often blocked off bysigns or vegetation. Such blockages prevent the target from beingobservable in the field of view of the driver or driver assistancesystem in the vehicle. While a presently available driver assistancesystem may be able to detect the obstruction created by the sign or thevegetation, the system is unable to detect targets that are obfuscatedby the obstruction, or are not yet in the field of view or range of thesystem.

The illustrative embodiments recognize that in many cases, a target canapproach a vehicle from an undetectable angle, from behind anobstruction, or from a distance, where the presently availablevehicle-based sonar, radar, laser, or visual imaging technology iseither of no use in detecting the target, or is unreliable in detectingthe target, or reliably detects the target too late to avoid acollision.

The illustrative embodiments used to describe the invention generallyaddress and solve the above-described problems and other problemsrelated to avoiding a collision between a target and a vehicle.

An embodiment can be implemented as a software application. Theapplication implementing an embodiment can be configured as amodification of an existing driver assistance system in a vehicle, as aseparate application that operates in conjunction with an existingdriver assistance system in a vehicle, as a modification of an existinglocation/activity monitoring module in a mobile device, as a separateapplication that operates in conjunction with an existinglocation/activity monitoring module in a mobile device, asplit-application between a system in a vehicle and a module in a mobiledevice, a standalone application, or some combination thereof.

Some embodiments are configured to operate in a mobile device associatedwith a target. A configuration where an embodiment operates in a mobiledevice is referred to herein as configuration 1. Some embodiments areconfigured to operate in a vehicle. A configuration where the embodimentoperates in a vehicle is referred to herein as configuration 2.

While the illustrative embodiments are described relative toconfiguration 1 or 2 specifically, the described embodiments are notlimited to only those configurations. An embodiment described relativeto configuration 1 can be implemented in configuration 2, and viceversa, within the scope of the illustrative embodiments. Furthermore, amobile device may implement the embodiments of configurations 1 and 2,and similarly, a vehicle may implement the embodiments of configurations1 and 2 within the scope of the illustrative embodiments.

A mobile device is associated with a target. The device is configuredwith a location module, which is able to determine the present locationof the device, and by association the location of the target, at anygiven time. As a non-limiting example, the location module may generatethe location coordinates of a location using the Global PositioningSystem (GPS), wireless triangulation, or some combination thereof. Anembodiment in configuration 1 uses the location information to determinewhether the target is located on a pathway where a possibility of acollision with a vehicle exists.

The device is also configured to detect an activity being performed bythe target. For example, the location module of the device may be ableand sufficient to determine that the target is stationary or moving.Optionally, an accelerometer or other motion sensing module may be ableto determine whether the target is walking, cycling, skating, or movingin other ways. An embodiment in configuration 1 optionally uses theactivity information to determine whether the target is moving relativeto the pathway, such as walking along the pathway or cycling on ortowards the pathway, such that a possibility of a collision between thetarget and a vehicle exists. Normally, but not always, a stationarytarget is relatively free of a possibility of a collision with a movingvehicle, a collision between a moving target and a stationary vehicle isalso relatively harmless, but a moving target can collide with a movingvehicle with undesirable results.

The device is also configured with a time module. The time module may bean implementation of a clock that provides time information. Anembodiment in configuration 1 optionally uses the time information todetermine whether the activity of the target is occurring during thedark hours of the day. An embodiment in configuration 1 can alsooptionally use a light sensing module (not shown) to determine an amountof ambient light around the target for a similar purpose.

The device is also configured with a communication module that iscapable of at least transmitting data wirelessly. An embodiment inconfiguration 1 uses the transmission capability of the communicationmodule to broadcast a signal. Optionally, the communication module mayalso be configured to receive data wirelessly. An embodiment inconfiguration 1 uses the reception capability of the communicationmodule to receive a broadcasted signal.

A signal according to the illustrative embodiments comprises specificdata broadcast from a mobile device, or from a vehicle. Specifically,the signal includes a unique identifier, a tag, and a present location.The identifier of the signal is unique within a given geographical areawhere the broadcasting device or vehicle is positioned at a given time.The tag is any suitable identifier sufficient to indicate that thesignal is meant for, or usable for, determining a position of thebroadcaster. The present location is the approximate location of thebroadcaster at the time of the broadcasting—i.e., during the negligibleperiod during which the signal is constructed and broadcast.

The Operations of Certain Embodiments are Described with Respect toConfiguration 1—

An embodiment determines whether a signal should be broadcast. Forexample, the embodiment uses the location information, the activityinformation, the time information, or some combination thereof to makethis determination. In one case, the embodiment broadcasts the signalregardless of where the target is located or the activity of the target,or the time of day. In another case, the embodiment broadcasts thesignal where the target is located on or near a pathway but regardlessof the activity of the target or the time of day.

In another case, the embodiment broadcasts the signal where the targetis located on or near a pathway and engaged in a movement on or relativeto the pathway but regardless of the time of day. In another case, theembodiment broadcasts the signal where the target is located on or neara pathway, is engaged in a movement on or relative to the pathway, andthe time of day is configured to be hazardous to the target with respectto vehicular collision.

In another case, the embodiment receives the broadcast signals from adefined vicinity of a target's device. The embodiment determines whetherother signals are being broadcast by others in the vicinity of thetarget. The embodiment omits the broadcasting when greater than athreshold number of other broadcasts are ongoing in the vicinity of thetarget. For example, when a person is moving with a crowd, if thedevices of other people are already broadcasting similar signals, thoseother signals are likely to have the same collision avoidance effectaccording to the illustrative embodiments for the entire crowd, and thetarget's device need not add another broadcast.

If a signal has to be broadcasted from the target's device, anotherembodiment determines how strong that broadcast should be. For example,the radio strength of the broadcast may be a factor of the time of theday, the type of pathway near the target, the number of other targets inthe vicinity of the target, the velocity of the target, and many othersignal strength factors.

As an example, the strength may have to exceed one threshold if thebroadcast is at night but may be below the threshold when made duringthe day. As another example, the strength may have to exceed onethreshold power if the target is traveling at a threshold speed orgreater, but may be below the threshold power when the speed is belowthe threshold speed. As another example, the strength may have to exceedone threshold power if less than a threshold number of other signals arepresent in the vicinity, i.e., the target may be alone, but may be belowthe threshold power when the number of other signals is at least thethreshold number.

These examples of signal strength factors and manners of determining thesame are not intended to be limiting. From this disclosure, those ofordinary skill in the art will be able to conceive many otheradjustments to the signal strength of a broadcast, and reasons therefor, and the same are contemplated within the scope of the illustrativeembodiments.

Thus, an embodiment in configuration 1 decides whether to broadcast asignal, what data to broadcast in the signal, and how powerfully thesignal should be broadcast. If a signal should be broadcast, theembodiment configures and broadcasts a signal with appropriate data at adetermined strength. Periodically, the embodiment re-determines whetherto broadcast a signal, what data to broadcast in the signal, and howpowerfully the signal should be broadcast. The embodiment periodicallyconfigures and broadcasts appropriate signals until the embodimentdetermines that a signal should not be broadcast.

The Operations of Certain Embodiments are Described with Respect toConfiguration 2—

A vehicle is configured with a location module, which is able todetermine the present location of the vehicle at any given time. As anon-limiting example, the location module may generate the locationcoordinates of a location using GPS, wireless triangulation, or somecombination thereof. An embodiment in configuration 2 uses the locationinformation in conjunction with a received broadcast of a signal from atarget's device to determine whether the target is located on a pathwaywhere a possibility of a collision with the vehicle exists.

The vehicle is also configured to detect a velocity of the vehicle. Forexample, the location module of the device may be able and sufficient todetermine that the target is stationary or moving in a direction with acertain speed. Optionally, an accelerometer or other motion sensingmodule may be able to determine similar information about the movementof the vehicle. An embodiment in configuration 2 optionally uses thevelocity information and the received signal from a target's device todetermine whether the target is moving relative to the pathway on whichthe vehicle is traveling or expected to travel.

The vehicle is also configured with a mapping module. The mapping moduleapplies or plots the vehicle's position and velocity, and the target'sposition and velocity, on a map. An embodiment in configuration 2optionally uses the plot information to determine whether a projectedpath of the target and a projected path of the vehicle intersect andcreate a risk of collision.

The vehicle is also configured with a communication module that iscapable of at least receiving data wirelessly. An embodiment inconfiguration 2 uses the reception capability of the communicationmodule to receive a broadcast of a signal from a device associated witha target.

Optionally, the communication module may also be configured to transmitdata wirelessly. An embodiment in configuration 2 uses the transmissioncapability of the communication module to broadcast a signal in a mannersimilar to broadcasting a signal from a device. A signal from thevehicle allows an embodiment in configuration 1 to similarlydetermine—on the device of a target—whether the projected path of thetarget can be expected to intersect with the projected path of thevehicle, creating a risk of collision.

An embodiment in configuration 2 detects or otherwise receives a signal.The embodiment analyzes the signal to determine a position and velocityof the target, e.g., by plotting the data of the signal on a map.

The embodiment determines whether a path of the vehicle intersects witha path of the target. For example, the embodiment plots the vehicle'sposition and velocity, and computes a projected path and expected timeto travel to certain point or points on that path. The embodimentsimilarly determines one or more broadcasts of one or more signals fromthe target's device to determine the target's position and velocity. Theembodiment plots the target's position and velocity and computes thetarget's projected path and expected time to travel to certain point orpoints on that path. The embodiment determines whether the vehicle andthe target arrive at a common point after a common amount of elapsedtime, thereby creating a risk of a collision.

In operation, the embodiment may receive multiple signals from multipletargets. The embodiment determines, in the above-described manner, whichof the targets poses a risk of collision and at which point ofintersection, given that target's projected path and times.

An embodiment further performs collision risk analysis. Assume thatmultiple targets are on various projected paths that intersect with theprojected path of the vehicle. The collision risk analysis determines alikelihood of each such target's path interesting with the vehicle'spath. To compute the likelihood, the embodiment uses a set of riskfactors.

A risk factor is a factor that reduces or increases a risk of collision.Some non-limiting examples of a risk factor are described herein. Forexample, a speed of travel of the target is a risk factor becausegenerally, the faster the target is traveling the higher the risk is ofa collision.

As another example, an acceleration (or deceleration) of the target is arisk factor because generally, a target that is speeding up is at ahigher risk of a collision than a target that is slowing down. Asanother example, visibility of the target is a risk factor becausegenerally, a target that is occluded or obscured is at a higher risk ofa collision than a target that is visible. The occlusions orobstructions between the vehicle and the target can be determined usingsatellite imagery from the map data in the mapping module. The greaterthe degree of occlusion between the vehicle and the target up to thepoint of intersection, the higher the risk, and vice versa.

As another example, an obstruction in the path of the target is a riskfactor because generally, a target that is unobstructed—and hence cancontinue on the path without stopping or slowing down for theobstruction—is at a higher risk of a collision than a target that isobstructed. Some examples of the obstructions are traffic lights,traffic signs, barricades, crosswalks and other traffic control devices.

Obstruction-based risk factors can be evaluated differently underdifferent circumstances. Suppose that a vehicle where an embodiment isexecuting is approaching a stop sign obstruction. As one example, byconsidering the vehicle's speed and proximity to an obstruction, theembodiment may determine that the vehicle is not slowing down at adesired deceleration, thereby increasing the risk of a collision with apedestrian that is approaching the intersection where the stop sign islocated. As another example, by considering the vehicle's speed andproximity to an obstruction, the embodiment may determine that thevehicle is slowing down at a desired deceleration, thereby decreasingthe risk of a collision with a pedestrian that is approaching theintersection where the stop sign is located. As another example, byconsidering the cyclist's speed and proximity to an obstruction, theembodiment may determine that the cyclist is not slowing down at adesired deceleration, thereby increasing the risk of a collision withthe vehicle where the embodiment is executing. As another example, byconsidering the cyclist's speed and proximity to an obstruction, theembodiment may determine that the cyclist is slowing down at a desireddeceleration, thereby decreasing the risk of a collision with thevehicle where the embodiment is executing.

As another example, the weather condition at the time is a risk factorbecause generally, a target that is traveling in undesirableweather—such as fog or rain—is at a higher risk of a collision than atarget that is traveling in desirable weather.

As another example, the historical information about the projected pathof the vehicle may be a risk factor. For example, the historicalinformation about past collisions on the path may indicate that the pathhas more than a threshold number of collision incidents, making the riskof collision more likely on the path.

As another example, the historical information about a target may be arisk factor. For example, the historical information about collisionsrelated to signals from a particular device may indicate that the targethas been involved in more than a threshold number of collisionincidents, making the risk of collision with the target more likely onthe path.

These examples of risk factors are not intended to be limiting. Fromthis disclosure, those of ordinary skill in the art will be able toconceive many other risk factors and the same are contemplated withinthe scope of the illustrative embodiments.

When a risk or likelihood of collision of greater than a thresholdlikelihood is identified between the vehicle and a target, an embodimentnotifies a system in the vehicle or an operator of the vehicle. Forexample, the notification may be sent to an actuation system that causesthe velocity of the vehicle to change.

When the embodiment is implemented in configuration 1, the embodimentnotifies the target or an actuation system associated with the target.The notification essentially informs about the risk of collision, butcan be configured to include additional information as may be desirableor suitable in a given implementation. For example, the notification caninclude the present locations of the vehicle and the target, theprojected intersection point, time to the intersection point, riskfactors, and many other pieces of information depending upon theimplementation.

An embodiment in configuration 1 or 2 can be enabled to contribute riskof collision data to a historical repository. For example, when anactual collision occurs, or a risk of collision is detected at greaterthan a threshold likelihood, the embodiment sends to the historicalrepository, the location and velocity information of the vehicle and thetarget, risk factors, signal information, or some combination thereof.The embodiment may normalize the data before contributing to thehistorical repository, e.g., by removing personally identifyinginformation about the vehicle or the target.

A method of an embodiment described herein, when implemented to executeon a device or data processing system, comprises substantial advancementof the functionality of that device or data processing system inavoiding a collision between vehicle and a target. For example,presently available methods for collision avoidance rely on detectingthe presence of a target in the vehicle-implemented driver assistancesystem's field of view. An embodiment provides a method by which anobscured target outside a vehicle-based system's field of view can bedetected, and a collision with such target can be forecasted withcorresponding likelihood. This manner of avoiding vehicle collisionusing signals from mobile devices is unavailable in the presentlyavailable methods. Thus, a substantial advancement of such devices ordata processing systems by executing a method of an embodiment is inimproved collision avoidance between vehicles and targets.

The illustrative embodiments are described with respect to certain typesof targets, vehicles, systems, signals, transmissions, analyses,projections, risks, likelihoods, factors, notifications, historicalinformation, modules, devices, data processing systems, environments,components, and applications only as examples. Any specificmanifestations of these and other similar artifacts are not intended tobe limiting to the invention. Any suitable manifestation of these andother similar artifacts can be selected within the scope of theillustrative embodiments.

Furthermore, the illustrative embodiments may be implemented withrespect to any type of data, data source, or access to a data sourceover a data network. Any type of data storage device may provide thedata to an embodiment of the invention, either locally at a dataprocessing system or over a data network, within the scope of theinvention. Where an embodiment is described using a mobile device, anytype of data storage device suitable for use with the mobile device mayprovide the data to such embodiment, either locally at the mobile deviceor over a data network, within the scope of the illustrativeembodiments.

The illustrative embodiments are described using specific code, designs,architectures, protocols, layouts, schematics, and tools only asexamples and are not limiting to the illustrative embodiments.Furthermore, the illustrative embodiments are described in someinstances using particular software, tools, and data processingenvironments only as an example for the clarity of the description. Theillustrative embodiments may be used in conjunction with othercomparable or similarly purposed structures, systems, applications, orarchitectures. For example, other comparable mobile devices, structures,systems, applications, or architectures therefor, may be used inconjunction with such embodiment of the invention within the scope ofthe invention. An illustrative embodiment may be implemented inhardware, software, or a combination thereof.

The examples in this disclosure are used only for the clarity of thedescription and are not limiting to the illustrative embodiments.Additional data, operations, actions, tasks, activities, andmanipulations will be conceivable from this disclosure and the same arecontemplated within the scope of the illustrative embodiments.

Any advantages listed herein are only examples and are not intended tobe limiting to the illustrative embodiments. Additional or differentadvantages may be realized by specific illustrative embodiments.Furthermore, a particular illustrative embodiment may have some, all, ornone of the advantages listed above.

With reference to the figures and in particular with reference to FIGS.1 and 2, these figures are example diagrams of data processingenvironments in which illustrative embodiments may be implemented. FIGS.1 and 2 are only examples and are not intended to assert or imply anylimitation with regard to the environments in which differentembodiments may be implemented. A particular implementation may makemany modifications to the depicted environments based on the followingdescription.

FIG. 1 depicts a block diagram of a network of data processing systemsin which illustrative embodiments may be implemented. Data processingenvironment 100 is a network of computers in which the illustrativeembodiments may be implemented. Data processing environment 100 includesnetwork 102. Network 102 is the medium used to provide communicationslinks between various devices and computers connected together withindata processing environment 100. Network 102 may include connections,such as wire, wireless communication links, or fiber optic cables.

Clients or servers are only example roles of certain data processingsystems connected to network 102 and are not intended to exclude otherconfigurations or roles for these data processing systems. Server 104and server 106 couple to network 102 along with storage unit 108.Software applications may execute on any computer in data processingenvironment 100. Clients 110, 112, and 114 are also coupled to network102. A data processing system, such as server 104 or 106, or client 110,112, or 114 may contain data and may have software applications orsoftware tools executing thereon.

Only as an example, and without implying any limitation to sucharchitecture, FIG. 1 depicts certain components that are usable in anexample implementation of an embodiment. For example, servers 104 and106, and clients 110, 112, 114, are depicted as servers and clients onlyas example and not to imply a limitation to a client-serverarchitecture. As another example, an embodiment can be distributedacross several data processing systems and a data network as shown,whereas another embodiment can be implemented on a single dataprocessing system within the scope of the illustrative embodiments. Dataprocessing systems 104, 106, 110, 112, and 114 also represent examplenodes in a cluster, partitions, and other configurations suitable forimplementing an embodiment.

Device 132 is an example of a device described herein. For example,device 132 can take the form of a smartphone, a tablet computer, alaptop computer, client 110 in a stationary or a portable form, awearable computing device, or any other suitable device. Any softwareapplication described as executing in another data processing system inFIG. 1 can be configured to execute in device 132 in a similar manner.Any data or information stored or produced in another data processingsystem in FIG. 1 can be configured to be stored or produced in device132 in a similar manner.

Automobile 142 is an example of a vehicle described herein and includesa system on which an embodiment described herein can be implemented. Forexample, application 144 in vehicle 142 implements an embodimentdescribed herein with respect to configuration 2. Device 132 isassociated with a target as described herein. Application 134 implementsan embodiment described herein with respect to configuration 1. Noteagain that vehicle 142 can also implement configuration 1 andembodiments there for, and device 132 can also implement configuration 2and embodiments there for. Generally, vehicle 142 and device 132 caneach implement configuration 1, configuration 2, or both configurations1 and 2, within the scope of the illustrative embodiments. Historicaldata 109 is usable by an embodiment in application 134 or application144 in a manner described herein.

Servers 104 and 106, storage unit 108, and clients 110, 112, and 114 maycouple to network 102 using wired connections, wireless communicationprotocols, or other suitable data connectivity. Clients 110, 112, and114 may be, for example, personal computers or network computers.

In the depicted example, server 104 may provide data, such as bootfiles, operating system images, and applications to clients 110, 112,and 114. Clients 110, 112, and 114 may be clients to server 104 in thisexample. Clients 110, 112, 114, or some combination thereof, may includetheir own data, boot files, operating system images, and applications.Data processing environment 100 may include additional servers, clients,and other devices that are not shown.

In the depicted example, data processing environment 100 may be theInternet. Network 102 may represent a collection of networks andgateways that use the Transmission Control Protocol/Internet Protocol(TCP/IP) and other protocols to communicate with one another. At theheart of the Internet is a backbone of data communication links betweenmajor nodes or host computers, including thousands of commercial,governmental, educational, and other computer systems that route dataand messages. Of course, data processing environment 100 also may beimplemented as a number of different types of networks, such as forexample, an intranet, a local area network (LAN), or a wide area network(WAN). FIG. 1 is intended as an example, and not as an architecturallimitation for the different illustrative embodiments.

Among other uses, data processing environment 100 may be used forimplementing a client-server environment in which the illustrativeembodiments may be implemented. A client-server environment enablessoftware applications and data to be distributed across a network suchthat an application functions by using the interactivity between aclient data processing system and a server data processing system. Dataprocessing environment 100 may also employ a service orientedarchitecture where interoperable software components distributed acrossa network may be packaged together as coherent business applications.

With reference to FIG. 2, this figure depicts a block diagram of a dataprocessing system in which illustrative embodiments may be implemented.Data processing system 200 is an example of a computer, such as servers104 and 106, or clients 110, 112, and 114 in FIG. 1, or another type ofdevice in which computer usable program code or instructionsimplementing the processes may be located for the illustrativeembodiments.

Data processing system 200 is also representative of a data processingsystem or a configuration therein, such as data processing system 132and vehicle 142 in FIG. 1 in which computer usable program code orinstructions implementing the processes of the illustrative embodimentsmay be located. Data processing system 200 is described as a computeronly as an example, without being limited thereto. Implementations inthe form of other devices, such as device 132 or vehicle 142 in FIG. 1,may modify data processing system 200, such as by adding a touchinterface, and even eliminate certain depicted components from dataprocessing system 200 without departing from the general description ofthe operations and functions of data processing system 200 describedherein.

In the depicted example, data processing system 200 employs a hubarchitecture including North Bridge and memory controller hub (NB/MCH)202 and South Bridge and input/output (I/O) controller hub (SB/ICH) 204.Processing unit 206, main memory 208, and graphics processor 210 arecoupled to North Bridge and memory controller hub (NB/MCH) 202.Processing unit 206 may contain one or more processors and may beimplemented using one or more heterogeneous processor systems.Processing unit 206 may be a multi-core processor. Graphics processor210 may be coupled to NB/MCH 202 through an accelerated graphics port(AGP) in certain implementations.

In the depicted example, local area network (LAN) adapter 212 is coupledto South Bridge and I/O controller hub (SB/ICH) 204. Audio adapter 216,keyboard and mouse adapter 220, modem 222, read only memory (ROM) 224,universal serial bus (USB) and other ports 232, and PCI/PCIe devices 234are coupled to South Bridge and I/O controller hub 204 through bus 238.Hard disk drive (HDD) or solid-state drive (SSD) 226 and CD-ROM 230 arecoupled to South Bridge and I/O controller hub 204 through bus 240.PCI/PCIe devices 234 may include, for example, Ethernet adapters, add-incards, and PC cards for notebook computers. PCI uses a card buscontroller, while PCIe does not. ROM 224 may be, for example, a flashbinary input/output system (BIOS). Hard disk drive 226 and CD-ROM 230may use, for example, an integrated drive electronics (IDE), serialadvanced technology attachment (SATA) interface, or variants such asexternal-SATA (eSATA) and micro-SATA (mSATA). A super I/O (SIO) device236 may be coupled to South Bridge and I/O controller hub (SB/ICH) 204through bus 238.

Memories, such as main memory 208, ROM 224, or flash memory (not shown),are some examples of computer usable storage devices. Hard disk drive orsolid state drive 226, CD-ROM 230, and other similarly usable devicesare some examples of computer usable storage devices including acomputer usable storage medium.

An operating system runs on processing unit 206. The operating systemcoordinates and provides control of various components within dataprocessing system 200 in FIG. 2. The operating system may be acommercially available operating system such as AIX® (AIX is a trademarkof International Business Machines Corporation in the United States andother countries), Microsoft® Windows® (Microsoft and Windows aretrademarks of Microsoft Corporation in the United States and othercountries), Linux® (Linux is a trademark of Linus Torvalds in the UnitedStates and other countries), iOS™ (iOS is a trademark of Cisco Systems,Inc. licensed to Apple Inc. in the United States and in othercountries), or Android™ (Android is a trademark of Google Inc., in theUnited States and in other countries). An object oriented programmingsystem, such as the Java™ programming system, may run in conjunctionwith the operating system and provide calls to the operating system fromJava™ programs or applications executing on data processing system 200(Java and all Java-based trademarks and logos are trademarks orregistered trademarks of Oracle Corporation and/or its affiliates).

Instructions for the operating system, the object-oriented programmingsystem, and applications or programs, such as application 134 and 144 inFIG. 1, are located on storage devices, such as in the form of code 226Aon hard disk drive 226, and may be loaded into at least one of one ormore memories, such as main memory 208, for execution by processing unit206. The processes of the illustrative embodiments may be performed byprocessing unit 206 using computer implemented instructions, which maybe located in a memory, such as, for example, main memory 208, read onlymemory 224, or in one or more peripheral devices.

Furthermore, in one case, code 226A may be downloaded over network 201Afrom remote system 201B, where similar code 201C is stored on a storagedevice 201D. in another case, code 226A may be downloaded over network201A to remote system 201B, where downloaded code 201C is stored on astorage device 201D.

The hardware in FIGS. 1-2 may vary depending on the implementation.Other internal hardware or peripheral devices, such as flash memory,equivalent non-volatile memory, or optical disk drives and the like, maybe used in addition to or in place of the hardware depicted in FIGS.1-2. In addition, the processes of the illustrative embodiments may beapplied to a multiprocessor data processing system.

In some illustrative examples, data processing system 200 may be apersonal digital assistant (PDA), which is generally configured withflash memory to provide non-volatile memory for storing operating systemfiles and/or user-generated data. A bus system may comprise one or morebuses, such as a system bus, an I/O bus, and a PCI bus. Of course, thebus system may be implemented using any type of communications fabric orarchitecture that provides for a transfer of data between differentcomponents or devices attached to the fabric or architecture.

A communications unit may include one or more devices used to transmitand receive data, such as a modem or a network adapter. A memory may be,for example, main memory 208 or a cache, such as the cache found inNorth Bridge and memory controller hub 202. A processing unit mayinclude one or more processors or CPUs.

The depicted examples in FIGS. 1-2 and above-described examples are notmeant to imply architectural limitations. For example, data processingsystem 200 also may be a tablet computer, laptop computer, or telephonedevice in addition to taking the form of a mobile or wearable device.

Where a computer or data processing system is described as a virtualmachine, a virtual device, or a virtual component, the virtual machine,virtual device, or the virtual component operates in the manner of dataprocessing system 200 using virtualized manifestation of some or allcomponents depicted in data processing system 200. For example, in avirtual machine, virtual device, or virtual component, processing unit206 is manifested as a virtualized instance of all or some number ofhardware processing units 206 available in a host data processingsystem, main memory 208 is manifested as a virtualized instance of allor some portion of main memory 208 that may be available in the hostdata processing system, and disk 226 is manifested as a virtualizedinstance of all or some portion of disk 226 that may be available in thehost data processing system. The host data processing system in suchcases is represented by data processing system 200.

With reference to FIG. 3, this figure depicts a block diagram of anexample configuration for avoiding vehicle collision using signals frommobile devices in accordance with an illustrative embodiment.Application 302 is an example of application 134 in FIG. 1 and isconfigured in configuration 1 as described herein. Application 302 canalso be implemented in application 144 in FIG. 1 and configured inconfiguration 2 as described herein, within the scope of theillustrative embodiments. Application 352 is an example of application144 in FIG. 1 and is configured in configuration 2 as described herein.Application 302 can also be implemented in application 144 in FIG. 1 andconfigured in configuration 1 as described herein, within the scope ofthe illustrative embodiments.

Application 302 uses one or more of location module 304, communicationmodule 306, motion sensing module 308, and time module 310 as describedherein. Using one or more modules 304-310 as described herein, component312 determines whether a broadcast of a signal should be made. If abroadcast should be made, component 314 constructs a signal using thelocation information from location module 304 in the signal data.Component 316 evaluates a set of signal strength factors using the datafrom one or more of modules 304-310 as described herein, and configurescommunication model 306 to an appropriate radio transmission power.Component 316 is optional when the broadcast is configured to occur at adefault power setting.

Application 302 wirelessly broadcasts signal 318 if component 312 hasdetermined that the broadcast should be performed. From time to time,application 302 broadcasts signal 318 with revised data pertinent at thetime. In one embodiment, subsequent broadcasts of signal 318 are afunction of a velocity of configuration 1. For example, if the velocityof the target increases, the time gap between consecutive signalsdecreases, and vice versa.

Application 352 uses one or more of location module 354, communicationmodule 356, motion sensing module 358, and mapping module 360 asdescribed herein. When configurations 1 and 2 are implemented in thesame system, e.g., in vehicle 142 or in device 132, location modules 304and 354 can be one and the same, communication modules 306 and 356 canbe one and the same, and motion sensing modules 308 and 358 can be oneand the same.

Component 362 detects signal 318. Component 364 analyzes one or moreinstances of signal 318 as described herein.

Using one or more modules 354-360 and the analyzed signal data asdescribed herein, component 366 determines whether the projected pathsof the vehicle and the target intersect at a common point and commontime. If the paths intersect, component 368 computes a likelihood orrisk of collision as described herein. If the likelihood exceeds athreshold likelihood, component 370 notifies a person—e.g. the driver ofthe vehicle or the target. Component 372 contributes the signal data,the risk data, factors data, or some combination of a normalized formthereof, to a historical repository, e.g., in the form of historicaldata 109 to repository 108 in FIG. 1.

With reference to FIG. 4A, this figure depicts a position plotting usingmap data in accordance with an illustrative embodiment. Map 402 may beobtained from mapping module 360 in FIG. 3. Application 352 performs theplotting on map 402 as shown.

Assume as an example that vehicle V implements configuration 2, andapplication 352 therein. The application plots the position of vehicle Vwhen signals from multiple targets—A, B, C, D, E, F, G, H, and I—arereceived by the application. By analyzing the signals from the varioustargets, the application plots the positions of those targets asdetermined from their signals received at the application. The positionsof the targets A-I are plotted relative to the position of vehicle V onmap 402 as shown.

With reference to FIG. 4B, this figure depicts a velocity plotting usingmap data in accordance with an illustrative embodiment. Map 402 may beobtained from mapping module 360 in FIG. 3. Application 352 performs theplotting on map 402 as shown.

By analyzing one or more signals received from each of targets A-I, theapplication plots their speed and direction. Only to visually express aninventive operation described herein, the speed of a target is shown onmap 402 as the lengths of the arrow and the direction of movement isindicated by the direction of the arrow originating from a target'sposition. Note that such visual representation on a visual map is notnecessary for the functioning of an embodiment, and may be omitted in animplementation without departing the scope of the illustrativeembodiments.

The analysis reveals that targets B, D, and G are broadcasting but arestationary. The analysis further shows that targets A, C, E, F, H, and Iare moving in various directions at various speeds relative to vehicleV.

With reference to FIG. 4C, this figure depicts a map plotting of a riskof collision in accordance with an illustrative embodiment. Map 402 maybe obtained from mapping module 360 in FIG. 3. Application 352 performsthe plotting on map 402 as shown.

Intercept detection function of the application determines that vehicleV is projected to travel on the path identified by the arrow based atvehicle V, as shown. If a route navigation is planned, the applicationcan also determine whether vehicle V will continue on the presentpathway or leave the present pathway and turn onto another pathway inthe projected path. The application then determines the potentialintersections in the projected path including the turns and changes inthe pathway.

Intercept detection function of the application determines that giventheir directions of travel, the projected paths of targets A, C, and Iwill likely not Intersect with the projected path of vehicle V.Intercept detection function of the application determines that giventheir directions of travel, the projected paths of targets E, F, and Hwill likely intersect with the projected path of vehicle V.

Collision analysis function of the application evaluates the variousrisk factors that may be applicable to each of targets E, F, and H todetermine the likelihood or the risk of collision with vehicle V. Assumeas an example that target E is a cyclist on a side path, target F is asoccer player in a backyard, and target H is a pedestrian on a crossstreet. Further assume that there are two thresholds of likelihood on ascale of 0 to 1, namely 0.33 and o.66.

Using one or more of the risk factors described herein, e.g., thevelocity of the target, the application determines that target E has alikelihood of 0.7 and target H has a likelihood of 0.5. Similarly, usingone or more of the risk factors described herein, e.g., obstructions inthe path of the target, the application determines from a satelliteimage that target F is fenced-in and cannot easily access the pathway ofvehicle V from behind the fence. Therefore, the application determinesthat target F has likelihood of 0.1.

Thus, the application determines that the risk of collision with thecyclist on the side path is higher than the high threshold, the risk ofcollision with the soccer player is lower than the low threshold, andthe risk of collision with the pedestrian on the cross street is betweenthe two thresholds. Note that at time of the likelihood determinationaccording to an embodiment, none of targets E, F, or H may be in thefield of view of vehicle V and therefore may not even be detected by aprior-art driver assistance system in vehicle V.

With reference to FIG. 5, this figure depicts a flowchart of an exampleprocess for avoiding vehicle collision using signals from mobile devicesin accordance with an illustrative embodiment. Process 500 can beimplemented in application 352 in configuration 2 of FIG. 3.

For any one of a number of targets that may be broadcasting at any giventime, the application receives a signal from a target (block 502). Theapplication determines a position of the target relative to the positionof a system where the application is executing (a position of self)(block 504). The application analyzes the signal or multiple instancesof the signal received at different times, to determine a velocity,i.e., a speed and a direction, of the movement of the target (block506).

The application computes an intersection point between a projected pathof self and a projected path of the target (block 508). The computationof block 508 accounts for any navigation related direction changes ofself.

The application computes a likelihood or risk of collision with thetarget (block 510). The application accounts for any number of riskfactors that can play a role in the collision. When the likelihoodexceeds a threshold likelihood, the application sends a notification ofa risk of collision (block 512). The application may continue to monitoradditional broadcasts from the target to detect any changes in the pathor velocity of the target, or may end process 500 thereafter.

With reference to FIG. 6, this figure depicts a process for configuringand broadcasting a collision avoidance signal in accordance with anillustrative embodiment. Process 600 can be implemented in application302 in configuration 1 in FIG. 3.

The application determines a location and movement of a target (block602). The application determines whether the location and/or movement ofthe target justifies broadcasting of a collision avoidance signal (block604). If the broadcast is not justified (“No” path of block 604), theapplication ends process 600 thereafter or returns to block 602 tomonitor changes in the location and or movement of the target.

If the broadcast is justified (“Yes” path of block 604), the applicationanalyzes other signals in the vicinity of the target (block 606). Theapplication determines, given the presence or absence of other signalsin the vicinity, whether broadcast of a signal from the target isjustified (block 608). If the broadcast is not justified (“No” path ofblock 608), the application ends process 600 thereafter or returns toblock 602 to monitor changes in the location and or movement of thetarget.

If the broadcast is justified (“Yes” path of block 608), the applicationevaluates a set of signal strength factors (block 610). The applicationadjusts a strength of the signal based on the evaluation (block 612).The application broadcasts the signal (block 614). The application endsprocess 600 thereafter or returns to block 602 to monitor changes in thelocation and or movement of the target. If a change occurs in thelocation or movement of the target, the application uses process 600 tosend an updated signal as described herein.

Thus, a computer implemented method, system or apparatus, and computerprogram product are provided in the illustrative embodiments foravoiding vehicle collision using signals from mobile devices and otherrelated features, functions, or operations. Where an embodiment or aportion thereof is described with respect to a type of device, thecomputer implemented method, system or apparatus, the computer programproduct, or a portion thereof, are adapted or configured for use with asuitable and comparable manifestation of that type of device.

Where an embodiment is described as implemented in an application, thedelivery of the application in a Software as a Service (SaaS) model iscontemplated within the scope of the illustrative embodiments. In a SaaSmodel, the capability of the application implementing an embodiment isprovided to a user by executing the application in a cloudinfrastructure. The user can access the application using a variety ofclient devices through a thin client interface such as a web browser(e.g., web-based e-mail), or other light-weight client-applications. Theuser does not manage or control the underlying cloud infrastructureincluding the network, servers, operating systems, or the storage of thecloud infrastructure. In some cases, the user may not even manage orcontrol the capabilities of the SaaS application. In some other cases,the SaaS implementation of the application may permit a possibleexception of limited user-specific application configuration settings.

The present invention may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instructions by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

What is claimed is:
 1. A method comprising: determining at a firstsystem, at a first time, a location of a target associated with thefirst system; constructing a signal, data of the signal comprising (i) aunique identifier, (ii) an identifier indicative of a collisionavoidance nature of the signal, and (iii) the location of the target;and broadcasting the signal from the first system, the broadcastingcausing a second system to receive the signal; compute, using thelocation from the signal and a velocity of the first system, and furtherusing a location of the second system at the first time and a velocityof the second system at the first time, a likelihood of a collisionbetween the first system and the second system; send a notification fromthe second system about the likelihood of collision responsive to thelikelihood of collision exceeding a threshold likelihood; determining anamount of ambient light around the target; and causing an increase, at atransmitter module in the first system, responsive to the amount ofambient light being less than a threshold amount, a transmission powerfor the broadcasting.
 2. The method of claim 1, further comprising:detecting whether other signals are being broadcast by other systems atthe first time, the other systems being located in a definedgeographical area around the first system; and initiating theconstructing, responsive to less than a threshold number of othersignals being broadcast at the first time.
 3. The method of claim 1,further comprising: causing an increase, at a transmitter module in thefirst system, responsive to less than the threshold number of othersignals being broadcast, a transmission power for the broadcasting. 4.The method of claim 1, further comprising: re-determining at the firstsystem, at a second time, a changed location of the target; constructingsecond data of a second signal using the second location; andbroadcasting, at the second time, a second signal.
 5. The method ofclaim 4, further comprising: computing, at the first system, a velocityof the target using the location and the changed location; and adjustinga time gap between the broadcasting of the signal and the broadcastingof the second signal according to the velocity of the target.
 6. Themethod of claim 5, further comprising: causing an increase, at atransmitter module in the first system, responsive to the velocityexceeding a threshold velocity, a transmission power for thebroadcasting.
 7. The method of claim 1, further comprising: determiningwhether the target is moving at the first time, wherein the broadcastingis responsive to the target moving at the first time.
 8. The method ofclaim 1, wherein the signal further comprises a timestamp correspondingto a time when the target was at the location of the target.
 9. Themethod of claim 1, wherein the unique identifier is unique within adefined geographical area around the target.
 10. The method of claim 1,wherein the signal further includes the velocity of the target.
 11. Themethod of claim 1, wherein the first system is a mobile deviceassociated with the target.
 12. A computer usable program productcomprising one or more computer-readable storage devices, and programinstructions stored on at least one of the one or more storage devices,the stored program instructions comprising: program instructions todetermine at a first system, at a first time, a location of a targetassociated with the first system; program instructions to construct asignal, data of the signal comprising (i) a unique identifier, (ii) anidentifier indicative of a collision avoidance nature of the signal, and(iii) the location of the target; and program instructions to broadcastthe signal from the first system, the broadcasting causing a secondsystem to program instructions to receive the signal; programinstructions to compute, using the location from the signal and avelocity of the first system, and further using a location of the secondsystem at the first time and a velocity of the second system at thefirst time, a likelihood of a collision between the first system and thesecond system; program instructions to send a notification from thesecond system about the likelihood of collision responsive to thelikelihood of collision exceeding a threshold likelihood programinstructions to determine an amount of ambient light around the target;and program instructions to cause an increase, at a transmitter modulein the first system, responsive to the amount of ambient light beingless than a threshold amount, a transmission power for the broadcasting.13. The computer usable program product of claim 12, further comprising:program instructions to detect whether other signals are being broadcastby other systems at the first time, the other systems being located in adefined geographical area around the first system; and programinstructions to initiate the constructing, responsive to less than athreshold number of other signals being broadcast at the first time. 14.The computer usable program product of claim 12, further comprising:program instructions to cause an increase, at a transmitter module inthe first system, responsive to less than the threshold number of othersignals being broadcast, a transmission power for the broadcasting. 15.The computer usable program product of claim 12, further comprising:program instructions to re-determine at the first system, at a secondtime, a changed location of the target; program instructions toconstruct second data of a second signal using the second location; andbroadcasting, at the second time, a second signal.
 16. The computerusable program product of claim 15, further comprising: programinstructions to compute, at the first system, a velocity of the targetusing the location and the changed location; and program instructions toadjust a time gap between the broadcasting of the signal and thebroadcasting of the second signal according to the velocity of thetarget.
 17. The computer usable program product of claim 16, wherein thecomputer usable code is stored in a computer readable storage device ina data processing system, and wherein the computer usable code istransferred over a network from a remote data processing system.
 18. Thecomputer usable program product of claim 16, wherein the computer usablecode is stored in a computer readable storage device in a server dataprocessing system, and wherein the computer usable code is downloadedover a network to a remote data processing system for use in a computerreadable storage device associated with the remote data processingsystem.
 19. A computer system comprising one or more processors, one ormore computer-readable memories, and one or more computer-readablestorage devices, and program instructions stored on at least one of theone or more storage devices for execution by at least one of the one ormore processors via at least one of the one or more memories, the storedprogram instructions comprising: program instructions to determine at afirst system, at a first time, a location of a target associated withthe first system; program instructions to construct a signal, data ofthe signal comprising (i) a unique identifier, (ii) an identifierindicative of a collision avoidance nature of the signal, and (iii) thelocation of the target; and program instructions to broadcast the signalfrom the first system, the broadcasting causing a second system toprogram instructions to receive the signal; program instructions tocompute, using the location from the signal and a velocity of the firstsystem, and further using a location of the second system at the firsttime and a velocity of the second system at the first time, a likelihoodof a collision between the first system and the second system; programinstructions to send a notification from the second system about thelikelihood of collision responsive to the likelihood of collisionexceeding a threshold likelihood program instructions to determine anamount of ambient light around the target; and program instructions tocause an increase, at a transmitter module in the first system,responsive to the amount of ambient light being less than a thresholdamount, a transmission power for the broadcasting.